var btns = [
        document.getElementById("btn_panel"),
        document.getElementById("btn_publish"),
        document.getElementById("btn_article"),
        document.getElementById("btn_comment"),
        document.getElementById("btn_tag"),
        document.getElementById("btn_document"),
        document.getElementById("btn_link"),
        document.getElementById("btn_setting")
    ]

for (let i =0;i<8;i++){
    btns[i].onmouseover = function () {
        btns[i].style.backgroundColor = "#6E6E6E"
    }

    btns[i].onmouseleave = function (){
        btns[i].style.backgroundColor = "transparent"
    }
}

var leftDiv = document.getElementById("left_div");
var menuBtn = document.getElementById("btn_menu");

var flag = false;
menuBtn.onclick = function () {
    if (flag) {
        leftDiv.style.display = "block";
    } else {
        leftDiv.style.display = "none";
    }
    flag = !flag;
}
